Customize text for closed folds
I wanted to improve the standard Vim foldtext both to look better in GUI versions of Vim, and to make the folding work better with C-like languages (such as C++, Java and pov). The foldtext function below does three things: *Is less intrusive when displaying code, and right-aligns the number of lines in the fold. *Collapses folds that start and end on braces with everything between the braces replaced with {...}. *Tries to collapse multiline comments with the first non-blank line in the comment. Outstanding issues: *Right alignment may not work with signs turned on. *Tabs mess up the in-place display of the initial '{'. " Set a nicer foldtext function set foldtext=MyFoldText() function! MyFoldText() let line = getline(v:foldstart) if match( line, '^[ \t]*\(\/\*\|\/\/\)*/\\*[ \t]*$' ) 0 let initial = substitute( line, '^\([ \t]\)*\(\/\*\|\/\/\)\(.*\)', '\1\2', '' ) let linenum = v:foldstart + 1 while linenum < v:foldend let line = getline( linenum ) let comment_content = substitute( line, '^\([ \t\/\*]*\)\(.*\)$', '\2', 'g' ) if comment_content != '' break endif let linenum = linenum + 1 endwhile let sub = initial . ' ' . comment_content else let sub = line let startbrace = substitute( line, '^.*{[ \t]*$', '{', 'g') if startbrace '{' let line = getline(v:foldend) let endbrace = substitute( line, '^[ \t]*}\(.*\)$', '}', 'g') if endbrace '}' let sub = sub.substitute( line, '^[ \t]*}\(.*\)$', '...}\1', 'g') endif endif endif let n = v:foldend - v:foldstart + 1 let info = " " . n . " lines" let sub = sub . " " let num_w = getwinvar( 0, '&number' ) * getwinvar( 0, '&numberwidth' ) let fold_w = getwinvar( 0, '&foldcolumn' ) let sub = strpart( sub, 0, winwidth(0) - strlen( info ) - num_w - fold_w - 1 ) return sub . info endfunction I also use the following highlights with white backgrounded source to visually set the folds apart from non-folded lines, while trying to keep a nice aesthetic. highlight FoldColumn gui=bold guifg=grey65 guibg=Grey90 highlight Folded gui=italic guifg=Black guibg=Grey90 highlight LineNr gui=NONE guifg=grey60 guibg=Grey90 See also * Folding presents an overview of how to use folding References * Comments Here's what I use. I think that some of it might be good to merge in (especially the 'diff' folding section) but I'm not up do doing it right now. My goal was to have a very similar fold pattern for things like C code, but provide a good fallback for all other folds, and define something special for diff folding. I really like the way the author of this tip treats comments in a special way—I might need to use that idea. In my $HOME/vimfiles/ftplugin directory, I set up different file-types to use my different fold patterns. For example, in c.vim, I have 'let b:foldpat=1'. if has("folding") set foldtext=MyFoldText() function! MyFoldText() " for now, just don't try if version isn't 7 or higher if v:version < 701 return foldtext() endif " clear fold from fillchars to set it up the way we want later let &l:fillchars = substitute(&l:fillchars,',\?fold:.',,'gi') let l:numwidth = (v:version < 701 ? 8 : &numberwidth) if &fdm 'diff' let l:linetext= let l:foldtext='---------- '.(v:foldend-v:foldstart+1).' lines the same ----------' let l:align = winwidth(0)-&foldcolumn-(&nu ? Max(strlen(line('$'))+1, l:numwidth) : 0) let l:align = (l:align / 2) + (strlen(l:foldtext)/2) " note trailing space on next line setlocal fillchars+=fold:\ elseif !exists('b:foldpat') || b:foldpat 0 let l:foldtext = ' '.(v:foldend-v:foldstart).' lines folded'.v:folddashes.'|' let l:endofline = (&textwidth>0 ? &textwidth : 80) let l:linetext = strpart(getline(v:foldstart),0,l:endofline-strlen(l:foldtext)) let l:align = l:endofline-strlen(l:linetext) setlocal fillchars+=fold:- elseif b:foldpat 1 let l:align = winwidth(0)-&foldcolumn-(&nu ? Max(strlen(line('$'))+1, l:numwidth) : 0) let l:foldtext = ' '.v:folddashes let l:linetext = substitute(getline(v:foldstart),'\s\+$',,'') let l:linetext .= ' ---'.(v:foldend-v:foldstart-1).' lines--- ' let l:linetext .= substitute(getline(v:foldend),'^\s\+',,'') let l:linetext = strpart(l:linetext,0,l:align-strlen(l:foldtext)) let l:align -= strlen(l:linetext) setlocal fillchars+=fold:- endif return printf('%s%*s', l:linetext, l:align, l:foldtext) endfunction endif Another suggestion (less elaborated than above, tested for 7.2/7.3): set foldtext=MyFoldText() function MyFoldText() let nucolwidth = &fdc + &number*&numberwidth let winwd = winwidth(0) - nucolwidth - 5 let foldlinecount = foldclosedend(v:foldstart) - foldclosed(v:foldstart) + 1 let prefix = " _______>>> " let fdnfo = prefix . string(v:foldlevel) . "," . string(foldlinecount) let line = strpart(getline(v:foldstart), 0 , winwd - len(fdnfo)) let fillcharcount = winwd - len(line) - len(fdnfo) return line . repeat(" ",fillcharcount) . fdnfo endfunction This will display javadoc summaries in a fold and will skip over multiple single line comments and C-style comments to display a method signature as the foldtext. I make heavy use of syntax folding and fold javadoc comments and function definitions separately, so I can see both doc summaries and method signatures. I generally want to skip over non-javadoc comments which precede a method decl when I fold a method, so this does both, shows javadoc summary and skips other comments to just show method signature. This will also align the fold text portion after the number of lines being folded is displayed, so it cleans up the fold display significantly. function! GetFoldedHeader() let numlines_folded = v:foldend - v:foldstart + 1 let line_num = v:foldstart let firstline = getline(v:foldstart) let charline = matchstr(firstline, '^\s*\(<^!\|\w\+\)^{}*') " Handle javadoc style comments, display the javadoc summary as the foldtext if match(firstline, '^\s*\/\*\*') 0 if match(firstline, '^\s*\/\*\*\s*$') 0 let charline = substitute(getline(v:foldstart+1), '^\s*\**\s*', '(doc) ', '') let charline = substitute(charline, '\..*$', '.', '') else let charline = substitute(firstline, '\s*\/\*\*\s*', '', '') endif else " handle the special case of multiple single line comments if match(firstline, '^\s*\/\/') 0 if match(getline(v:foldend), '^\s*\/\/') 0 let charline = substitute(firstline, '\s*\/*\s*', '', '') endif else let charline = matchstr(firstline, '^\s*\(<^!\|\w\+\)^{}*') while strlen(charline) 0 && line_num < v:foldend let line_num = line_num + 1 let charline = matchstr(getline(line_num), '^\s*\(<^!\|\w\+\)^{}*') endw endif endif let preamble = printf("lines folded:", numlines_folded) return printf("%-20s%s", preamble, substitute(charline, '^\s*', '', ''))